1. Technical Field
The present disclosure relates to a resonant magnetic coupling type non-contact power transmission technology for transmitting electric power wirelessly using resonant magnetic coupling.
2. Description of the Related Art
U.S. Patent Application Publication No. 2008/0278264 (FIGS. 12 and 14) discloses a new type of wireless energy transfer system for transferring energy wirelessly (through a space) from one of two resonators to the other, and vice versa. That wireless energy transfer system couples those two resonators with each other via the evanescent tail of the oscillation energy of the resonant frequency that is produced in the space surrounding those two resonators, thereby transferring the oscillation energy wirelessly (i.e., by a non-contact method).
Meanwhile, the traditional electromagnetic induction technology is still used today. Many of electronic devices, to which these electric power transmission technologies are applied, often demand supply of a constant voltage after having received electric power with a constant voltage and gone through some kind of power conversion, voltage division, energy transfer and other blocks. For example, as for an audiovisual device such as a TV set, such a device usually receives electric power through an AC outlet that supplies AC power with a substantially constant voltage and individual circuits in the device, which eventually consume the power supplied, operate with a predetermined voltage maintained. Even if the brightness on the screen has varied, such a variation can also be coped with by changing the amount of current to flow. Such an operation of receiving electric power with a constant voltage from a power supply and outputting the power with the constant voltage to a load will be referred to herein as a “constant voltage operation”.